There's a block in AE called a
Storage Bus which lets you use a different form of storage but that the AE system can access it. I haven't used it yet. I hope that for barrels you don't need to have one on top and one on the bottom. I can't check right now, I'm afraid!
no problems thats all i needed to know
the setup this guy has is like follows.
B-B-B-B-B-B-B-B-B-X
|-------------------- |
B-------------------- B
|-------------------- |
B-------------------- B
|-------------------- |
B-B-B-B-B-B-B-B-B-B
this would be see when you looked at it from top while floating above it.
"B" marks the spots/lines where the barrels are located and the "X" on the top right is where he did put the Storage Bus.
/edit
ok quick addendum after rewatching the episodes where this was covered in RedLeds lets play.
where the X is there is a chest that is designated to be the default route for his barrel storage system and to this chest the bus is connected. (just adding this in case someone was wondering and planned to use a similar system)